The present invention relates to a flexible disk device, a disk formatting method, and a recording/reproducing method.
Conventionally, a large-capacity flexible disk device is known, in which recording and reproducing on and from both a high-capacity formatted recording medium and a low-capacity formatted recording medium, that are different in linear recording density and track density, are carried out.
For example, according to a large-capacity flexible disk device disclosed in Japanese Unexamined Patent Publication No. 3-156711, with respect to a high-capacity formatted recording medium, recording and reproducing is carried out by means of a high-capacity magnetic head and a data processing circuit for a high-capacity format, and with respect to a low-capacity formatted recording medium, recording and reproducing is carried out by means of a low-capacity magnetic head and a data processing circuit for a low-capacity format.
In Japanese Unexamined Patent Publication No. 3-156711, an attempt to write a greater quantity of information in a low-capacity formatted recording medium with a high-capacity magnetic head is described. However, since such high-capacity magnetic heads have a recording gap length that is conformable to a high-capacity formatted recording medium having a high linear recording density, a problem exists such that overwriting characteristics are degraded. Furthermore, of these, high-capacity magnetic heads which write in and read out information at a narrow data track width also have a problem such that an influence of displacement due to eccentricity and the like created during replacement of recording media is strongly exerted and data reproduction cannot be normally carried out.
Therefore, it has been an object to develop a technique such that by making full use of a plurality of types of magnetic heads and data processing circuits which are respectively installed in correspondence with a plurality of types of recording media having different capacities, data which is higher in capacity than the prior arts can be recorded in a low-capacity recording medium and the recorded data can be satisfactorily reproduced.
In order to achieve the above object, according to the present invention, a high-capacity track format is written in a low-capacity recording medium by a low-capacity magnetic head, information on the low-capacity recording medium is reproduced by a high-capacity magnetic head which corresponds to the written high-capacity track format, whereby it becomes possible to record data which is greater in capacity than the prior arts in the low-capacity recording medium and reproduce the recorded data satisfactorily.
That is, the present invention provides a flexible disk device comprising: a first magnetic head which has a wide recording gap width, and can write in and read out information, with respect to a low-capacity recording medium, at a wide track width based on the wide recording gap and in a low-capacity track format; and a second magnetic head which has a recording gap width that is narrower than that of the first magnetic head, and can write in and read out information, with respect to the high-capacity recording medium which is greater in capacity than the low-capacity recording medium, at a narrow track width based on the narrow recording gap and in a high-capacity track format which is greater in track density and linear density than the low-capacity recording medium, whereby the flexible disk device records and reproduces information on and from two or more types of recording media having different capacities, characterized in that a control means is provided for controlling the first magnetic head to operate at track intervals narrower than the recording gap width thereof so as to write a high-capacity track format in the low-capacity recording medium at a narrow track width, thereby to record information and to read out the information recorded on the low-capacity recording medium by the second magnetic head.
In addition, according to the present invention, the above-described flexible disk device comprises a third magnetic head which has a recording gap width that is narrower than that of the second magnetic head, and can read out information which has been recorded in a second high-capacity track format that is even greater in track density and linear density than the high-capacity track format that the second magnetic disk head can write in and read out, wherein the control controls the second magnetic head to operate at track intervals narrower than the recording gap width thereof so as to write a second high-capacity track format in the high-capacity recording medium at a narrow track width, thereby to record information and to read out the information recorded on the high-capacity recording medium by the third magnetic head.
In further detail, the above-described flexible disk device comprises a rotating means for rotating a recording medium which is placed thereon, a carriage which is loaded with the first and second magnetic heads, and data processing circuits for first and second formats which modulate information to be inputted in the first and second magnetic heads to data signals which correspond to a low-capacity or a high-capacity track format in accordance with designation and demodulate information read out by the respective magnetic heads, wherein the control means controls track positions of the first and second magnetic heads via the carriage and also selects either one of the data processing circuits for first and second formats.
In addition, the carriage is further loaded with a third magnetic head and includes a data processing circuit for a third format which demodulates information read out by the third magnetic head, wherein the control means controls track positions of the first, second, and third magnetic heads via the carriage and also selects any one of the data processing circuits for the first, second, and third formats.
In addition, the present invention provides a disk formatting method for formatting two or more types of recording media having different capacities, wherein with respect to a low-capacity recording medium, a first magnetic head which can write in and read out information in a low-capacity track format is operated at track intervals that are narrower than a recording gap width thereof, so as to write in a high-capacity track format which is greater in track density and linear density than the low-capacity track format.
Furthermore, the present invention provides a recording/reproducing method for recording and reproducing on and from two or more types of recording media having different capacities, wherein with respect to a low-capacity recording medium, a first magnetic head which can write in and read out information in a low-capacity track format is operated at track intervals that are narrower than a recording gap width thereof so as to write in a high-capacity track format which is greater in track density and linear density than the low-capacity track format, thereby to record information and to read out the information recorded on the low-capacity recording medium by a second magnetic head which can read out information in the high-capacity track format.
In general, a high-capacity magnetic head is designed to have a narrow recording gap length and a narrow gap width that are conformable to a high-capacity format that is high in linear recording density and track density, and is designed to write a high-capacity track format in a high-capacity recording medium at a narrow track width and at a high track density, thereby to record information and reproduce the recorded information. A low-capacity magnetic head which corresponds to this high-capacity magnetic head is designed to have a recording gap length and a gap width that are wider than those of the high-capacity magnetic head, write a low-capacity track format in a low-capacity recording medium at a wide track width and at a low track density, thereby to record information and reproduce the recorded information.
The recording media herein referred to are flexible disks, wherein as the low-capacity recording media, there are 2HD disks, 2DD disks and the like and as the high-capacity recording media, there are 240 MB super disks, 120 MB super disks and the like. In addition, the low-capacity magnetic heads utilized for 2HD disks and 2DD disks include high density heads (HD heads) and the like, and an example thereof is a head having a recording gap width of 115 xcexcm and track intervals of 187.5 xcexcm. The high-capacity magnetic heads utilized for 240 MB super disks and 120 MB super disks include ultra high density heads (UHD heads) and the like, and an example thereof is a head having a recording gap width of 8 xcexcm and track intervals of 10.2 xcexcm.
However, in the present DESCRIPTION, the words xe2x80x9clow-capacityxe2x80x9d and xe2x80x9chigh-capacityxe2x80x9d are used as words representing a relatively high capacity and a relatively low capacity, respectively.
According to the present invention, a high-capacity track format is written in a low-capacity recording medium by means of a low-capacity magnetic head, therefore, in spite of being at a wide track width corresponding to a recording gap width of the low-capacity magnetic head, format information and desirable information can be written at a high linear recording density and a high track density that are peculiar to the high-capacity track format. The information written in this low-capacity recording medium in the high-capacity track format is read out using a high-capacity magnetic head having a narrow recording gap width which corresponds to the high-capacity track format, therefore, even if track displacement occurs to some extent, the output does not drop and the information can be satisfactorily reproduced. Thus, it becomes possible to record data that is higher in capacity than the prior arts in a low-capacity recording medium and reproduce the data therefrom satisfactorily.